func_aes.c File Reference

AES encryption/decryption dialplan functions. More...

#include "asterisk.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/app.h"
#include "asterisk/aes.h"

Include dependency graph for func_aes.c:

Go to the source code of this file.

Defines
#define	AES_BLOCK_SIZE   16
Functions
static void	__reg_module (void)
static void	__unreg_module (void)
static int	aes_helper (struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
static int	load_module (void)
static int	unload_module (void)
Variables
static struct ast_module_info	__mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "AES dialplan functions" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "0901e4e500243c855563a2d78b0c03e4" , .load = load_module, .unload = unload_module, }
static struct ast_custom_function	aes_decrypt_function
static struct ast_custom_function	aes_encrypt_function
static struct ast_module_info *	ast_module_info = &__mod_info

---

Detailed Description

AES encryption/decryption dialplan functions.

Author:

David Vossel <dvossel@digium.com>

Definition in file func_aes.c.

---

Define Documentation

#define AES_BLOCK_SIZE   16

Definition at line 35 of file func_aes.c.

Referenced by aes_helper().

---

Function Documentation

static void __reg_module

(

void

)

[static]

Definition at line 163 of file func_aes.c.

static void __unreg_module

(

void

)

[static]

Definition at line 163 of file func_aes.c.

static int aes_helper	(	struct ast_channel *	chan,
		const char *	cmd,
		char *	data,
		char *	buf,
		size_t	len
	)			[static]

Definition at line 73 of file func_aes.c.

References AES_BLOCK_SIZE, ast_aes_decrypt, ast_aes_decrypt_key, ast_aes_encrypt, ast_aes_encrypt_key, AST_APP_ARG, ast_base64decode(), ast_base64encode(), ast_calloc, ast_copy_string(), AST_DECLARE_APP_ARGS, ast_free, ast_log(), AST_STANDARD_APP_ARGS, ast_strlen_zero(), and LOG_WARNING.

{
   unsigned char curblock[AES_BLOCK_SIZE] = { 0, };
   char *tmp;
   char *tmpP;
   int data_len, encrypt;
   ast_aes_encrypt_key ecx;                        /*  AES 128 Encryption context */
   ast_aes_decrypt_key dcx;

   AST_DECLARE_APP_ARGS(args,
      AST_APP_ARG(key);
      AST_APP_ARG(data);
   );

   AST_STANDARD_APP_ARGS(args, data);

   if (ast_strlen_zero(args.data) || ast_strlen_zero(args.key)) {
      ast_log(LOG_WARNING, "Syntax: %s(<key>,<data>) - missing argument!\n", cmd);
      return -1;
   }

   if (strlen(args.key) != AES_BLOCK_SIZE) {        /* key must be of 16 characters in length, 128 bits */
      ast_log(LOG_WARNING, "Syntax: %s(<key>,<data>) - <key> parameter must be exactly 16 characters!\n", cmd);
      return -1;
   }

   ast_aes_encrypt_key((unsigned char *) args.key, &ecx);   /* encryption:  plaintext -> encryptedtext -> base64 */
   ast_aes_decrypt_key((unsigned char *) args.key, &dcx);   /* decryption:  base64 -> encryptedtext -> plaintext */
   tmp = ast_calloc(1, len);                     /* requires a tmp buffer for the base64 decode */
   tmpP = tmp;
   encrypt = strcmp("AES_DECRYPT", cmd);           /* -1 if encrypting, 0 if decrypting */

   if (encrypt) {                                  /* if decrypting first decode src to base64 */
      ast_copy_string(tmp, args.data, len);
      data_len = strlen(tmp);
   } else {
      data_len = ast_base64decode((unsigned char *) tmp, args.data, len);
   }

   if (data_len >= len) {                        /* make sure to not go over buffer len */
      ast_log(LOG_WARNING, "Syntax: %s(<keys>,<data>) - <data> exceeds buffer length.  Result may be truncated!\n", cmd);
      data_len = len - 1;
   }

   while (data_len > 0) {
      memset(curblock, 0, AES_BLOCK_SIZE);
      memcpy(curblock, tmpP, (data_len < AES_BLOCK_SIZE) ? data_len : AES_BLOCK_SIZE);
      if (encrypt) {
         ast_aes_encrypt(curblock, (unsigned char *) tmpP, &ecx);
      } else {
         ast_aes_decrypt(curblock, (unsigned char *) tmpP, &dcx);
      }
      tmpP += AES_BLOCK_SIZE;
      data_len -= AES_BLOCK_SIZE;
   }

   if (encrypt) {                            /* if encrypting encode result to base64 */
      ast_base64encode(buf, (unsigned char *) tmp, strlen(tmp), len);
   } else {
      memcpy(buf, tmp, len);
   }
   ast_free(tmp);

   return 0;
}

static int load_module

(

void

)

[static]

Definition at line 156 of file func_aes.c.

References ast_custom_function_register, AST_MODULE_LOAD_DECLINE, and AST_MODULE_LOAD_SUCCESS.

{
   int res = ast_custom_function_register(&aes_decrypt_function);
   res |= ast_custom_function_register(&aes_encrypt_function);
   return res ? AST_MODULE_LOAD_DECLINE : AST_MODULE_LOAD_SUCCESS;
}

static int unload_module

(

void

)

[static]

Definition at line 150 of file func_aes.c.

References ast_custom_function_unregister().

{
   int res = ast_custom_function_unregister(&aes_decrypt_function);
   return res | ast_custom_function_unregister(&aes_encrypt_function);
}

---

Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "AES dialplan functions" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "0901e4e500243c855563a2d78b0c03e4" , .load = load_module, .unload = unload_module, } [static]

Definition at line 163 of file func_aes.c.

struct ast_custom_function aes_decrypt_function [static]

Initial value:

 {
   .name = "AES_DECRYPT",
   .read = aes_helper,
}

Definition at line 145 of file func_aes.c.

struct ast_custom_function aes_encrypt_function [static]

Initial value:

 {
   .name = "AES_ENCRYPT",
   .read = aes_helper,
}

Definition at line 140 of file func_aes.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 163 of file func_aes.c.